ML20072P809

Interim Deficiency Rept 82-09 Re Small Bore/Instrumentation Piping & Conduit Support Design Calculations.Initially Reported on 820902.Util Currently Reviewing Technical Adequacy of Sargent & Lundy Design.Next Rept within 90 Days

ML20072P809
Person / Time
Site:	Clinton
Issue date:	03/28/1983
From:	Hall D ILLINOIS POWER CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
10CFR-050.55E, 82-09, U-10040, NUDOCS 8304040382
Download: ML20072P809 (8)

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1605-L ILLIN0/8 POWER 00MPANY U-10040 CLINTON POWER STAflON, P.O. BOX 678, CLINTON, ILLINOIS 61727 March 28, 1983 Docket Number 50-461 Mr. James G. Keppler Regional Administrator Region III U.S. Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, Illinois 60137

Subject:

Potential Deficiency 82-09 10CFR50.55(e)

Small Bore / Instrumentation Piping, and Conduit Support Design Calculations

Dear Mr. Keppler:

On September 2, 1982, Illinois Power notified Mr. P. Pelke, NRC Region III (Ref: IP memorandum Y-13910, 1605-L, dated September 2, 1982) of a potentially reportable deficiency con-cerning discrepancies identified by Illinois Power in a sample of small bore / instrumentation piping support design calculations performed by Sargent & Lundy (CPS Architect-Engineer). This initial notification was followed by one (1) interim report (Ref:

IP letter, D. P. Hall to J. G. Keppler, U-0555, 1605-L, dated October 1, 1982). Further, a second interim report (Ref: IP letter, D. P. Hall to J. G. Keppler U-10014, 1605-L, dated December 21, 1982) was submitted, that expanded the scope of the potential deficiency to include similar discrepancies identified by Illinois Power in the Sargent & Lundy's calculations supporting the design of electrical conduit supports. Illinois Power's investigation of the above matter continues, and this letter is submitted as an interim report in accordance with 10CFR50.55(e)(3), to keep you informed of our progress.

1 Statement of Potentially Reportable Deficiency An independent review by Illinois Power Nuclear Station Engineering Department (NSED) of calculations performed by l Sargent & Lundy (S&L) for small bore / instrumentation piping l

8304040302 830328 T

{DR ADDCK 05000 g MAR 311983

T Mr. Jamss G. Ktppler .Page 2 March 28, 1983 i

supports and electrical conduit supports identified errors in the calculations used as the design basis. Resolution of the errors could result in changes to small bore / instrumentation piping supports, and electrical conduit supports released for construction, cn: require the installation of additional supports.

An evaluation is being performed to determine'(1) the magnitude and significance of these errors, (2) the potential for errors in other areas.of design performed by similar methods, (3) the-impact on installed hardware, and, (4) the potential for adverse impact on the safety of operations of Clinton Power Station (CPS), and reportability as a deficiency in final design under 10CFR50.55(e).

Background / Investigation Results Small Bore / Instrumentation Piping Supports During August, 1982, IP NSED reviewed a sample of twelve (12) small bore piping support calculations performed by S&L's on-site small bore piping design group. The calculations are performed to determine small bore pipe support loads, spans between supports, and flexibility for thermal growth. In the course of the review, NSED discovered errors in the calculations.

The type of errors identified included mathematical errors, errors in transposition of-measurements from design drawings for

. use in calculations, and errors in the selection of appropriate design inputs and rules provided in small bore pipe support design procedures. As a result of these findings, S&L performed a review of an additional thirty (30) calculations. This review found similar errors, several of which were in the non-conserv-ative direction. Accordingly, an examination of the issues was started.

Investigation into calculation discrepancies associated with small bore / instrumentation piping supports is continuing. A hold was placed by S&L on the release of small bore piping support design documents until the matter was fully investigated and corrective action was implemented. S&L has performed a review of the 324 safety-related small bore / instrumentation pipe calcu-lations performed to date and identified 134 calculations which

! contain non-conservative discrepancies to the requirements of the l S&L small piping procedure, EMD-015666. To evaluate error significance, these piping designs were further evaluated by S&L using computer analysis or detailed hand calculations, and the results showed compliance with the ASME Code. However, these calculations are being revised to conform with the rules of EMD-015666 in order to ensure that standard design parameters are used throughout the plant. This will result in some hardware changes. Further, twenty-five (25) calculations of small bore / instrumentation piping were found to be out of compliance with both EMD-015666 and the ASME Code. Calculation revisions are l

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Mr. Jamas G. Keppler Page 3 March 28, 1983 1

4 being made, and will result in hardware changes to bring the affected subsystems into compliance with EMD-015666 and the ASME Code. An S&L analysis of these 25 calculations has been performed, which showed that none of the discrepancies would affect adversely the safety of operation of CPS.

A special surveillance has been performed by Illinois Power QA and NSED to verify adequacy of corrective action taken by S&L on this matter. This surveillance showed that the corrective actions taken by S&L were adequate to prevent recurrence of the types of errors detected in the small bore / instrumentation piping support calculations. As a result of this positive evaluation, IP authorized S&L to lift the hold on release of design documents for small bore / instrumentation piping supports.

NSED is continuing its review of the technical adequacy of S&L's work in the area of small bore / instrumentation piping design as follows:

1. NSED recently completed, and is evaluating the results of a review of calculations that support and validate the S&L small bore piping procedure. This review was performed on February 15-18, 1983, with the assistance of Stone & Webster Engineering Corporation personnel, utilizing a checklist containing review attributes that reflect proper engineering and design control practices for performing small bore piping analysis. This review identified several areas of the procedure that require improvement or clarification. In addition, a potential problem has been identified with S&L's span and load tables for piping runs between the containment and the auxiliary building. The extent and impact, if any, of these problems is presently being evaluated.

2. NSED has implemented a program of on-going reviews of selected new small bore piping calculations performed by S&L during each month. Preliminary results thus far have indicated that the calculations are adequate.

3. NSED is tracking the resolution and status of hardware problems resulting from the calculation discrepancies.

This action will continue until all calculations requiring revision have been completed and hardware deficiencies are corrected.

4. NSED will perform a review of S&L's justification and supporting calculations with regard to impact on plant safety for those subsystems which did not meet ASME Code allowables. In addition, an analysis as to the safety significance of these subsystems will be performed by NSED.

Mr. James G. Keppler Page 4 March 28, 1983

5. NSED has performed a review of selected small bore /

instrumentation piping calculations performed under the original program that S&L assessed as technically adequate. Preliminary results from this review identified some minor problems, primarily with the legibility of the calculations. The impact of this problem is presently being evaluated.

Conduit Supports As a result of previously identified calculation errors in the area of small bore piping supports, NSED performed a review of a sample of S&L's conduit support calculations. This review was aerformed during the period September 14, 1982 through Octoier 22, 1982, and included a detailed review of one-hundred-twenty-five (125) electrical conduit support calculations, comprised of twenty five (25) selected from each of five (5) seismic category I buildings (auxiliary, control, diesel-generator, containment, and fuel). The results of this review are tabulated as follows:

I. Calculation conservative, support suitable.................... 68 II. Calculation discrepancy, support considered suitabic.......... 41 III. Calculation discrepancy, support not considered suitable....... 3 IV. Calculation discrepancy, support suitability indeterminate.... 13 Total calculations reviewed.................................. 125 An evaluation of the discrepancies identified in categories II, III, and IV was completed by S&L and showed that, although calculation discrepancies exist, the supports are adequate as designed. However, a hold was imposed by S&L on December 13, 1982 on conduit support calculation activities until corrective action was taken and verified to be acceptable by S&L QA, Illinois Power QA, and NSED.

Investigation into calculation discrepancies in the area of conduit supports is continuing. IPQA and NSED surveillances found that S&L's condait support procedures did not always provide standard methods for preparing and reviewing the calculations, therefore, reliance was placed on personal interpretation and engineering judgement to perform the tasks.

Additionally, calculations for conduit supports were not always prepared and reviewed properly, primarily due to insufficient attention to detail by the preparers and reviewers. S&L QA also performed an audit of conduit support calculation activities.

This audit identified errors of the same type as those identified by IP NSED in thirty-six (36) of forty-three (43) calculations reviewed. The results of both the IP surveillance and the S&L

s Mr. Jamns G. Keppler Page 5 March 28, 1983 audit identified a total of sixteen (16) errors in the calculations that resulted in support loads exceeding the limits of the standard' design tables. Further evaluation of these errors by S&L found that the supports affected by the calculations were adequate.

An additional concern was observed during the S&L assessment of calculational errors identified by IP USED and S&L QA. It was found that certain base assumptions used in conduit support design were not clearly shown on design drawings or in the electricel. installation specification, K-2999. As this information was not provided to Baldwin Associates (CPS Contractor) , an inspection of the related hardware attributes to verify conformance with the design assumptions was not made.

Therefore, the as-inetalled conduit supports may not agree with the supporting design calculations. An Engineering Change Notice (ECN 3360) has been issued to revise K-2999, to incorporate the necessary design information required to assure that conduit support '.nstallation agrees with. conduit design calculations. A reinspection of installed conduit supports will be performed to assure that the as-built hardware is in agreement with the new design information.

An IP QA and NSED surveillance has been performed to verify adequacy of corrective action taken by S&L. This surveillance showed that the corrective action taken by S&L was adequate in all areas of conduit support calculations, with the exception of four (4) types of supports (JS type box supports, TCC, TH, and THB trapeze type conduit supports). As a result of this evaluation, Illinois Power QA authorized S&L to release the hold on conduit support calculations in all but the four problem areas identified above.

NSED is continuing its review of the technical adequacy of S&L work in the area of conduit support design as follows:

1. S&L has submitted to NSED a set of sixteen (16) additional structural calculations prepared by S&L to show that the errors found in conduit support calculations by the NSED surveillance and S&L audit are l not significant and do not require hardware changes.

! These calculations are being reviewed by NSED for adequacy.

i l 2. Illinois Power QA and NSED are presently evaluating plans by S&L for performing evaluations of conduit support calculations performed prior to December 13, 1982.

3. NSED is evaluating calculations prepared by S&L as the

, basis for design tables contained in the conduit support design procedures, to determine the validity of the procedures.

s Mr. Jam s G. Kcppler Page 6 March 28, 1983 Corrective Action (Interim)

Illinois Power Company has met with Sargent & Lundy Project Management to discuss and develop a course of action to fully investigate the scope of the calculation errors, root causes of the errors, and impact on installed hardware. Several corrective action measures have been established and are being taken by Illinois Power and Sargent & Lundy, as follows:

Small Bore / Instrumentation {jping Supports

1. S&L procedures for small bore / instrumentation support design have been expanded and clarified to enhance the design process. These enhancements include:

instituting a checklist to be used by.the independent reviewer of calculations to assure an adequate review; locating analysts on site to review and concur with procedural interpretations; and location of copies of piping system stress reports at the site for first-hand reference.

2. Personnel responsible for preparing and reviewing small bore / instrumentation piping support calculations have been given training in the requirements of the revised procedures.

3. Calculations which contain nonconservative errors will be reconciled or revised. This action was authorized by Illinois Power to begin on December 20, 1982, and is .

estimated to be completed by July 29, 1983. Affected hardware will be revised and corrected as necessary.

4. Technical reviews by IP NSED will be performed on an on-going, sampling basis to assure technical adequacy of small bore piping support calculations performed by S&L.

Conduit Supports

5. A hold on electrical conduit support design activities l remains in effect for JS, TCC, TH, and THB type support

! calculations, until further investigation is performed and appropriate corrective actions have been taken and found acceptable by S&L QA, IP QA, and NSED.

6. S&L has issued a Project Instruction, PI-CP-045,

" Electrical Conduit and Conduit Support Design" that describes how conduit support design rules are to be l applied.

7. S&L has issued Electrical Department Administrative Procedure 35 that formalizes the training program

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. 'Mr. Jam:s G. Keppler Page 7 March 28, 1983 required for. conduit and conduit support designers.

This. training has been given to conduit and conduit support design personnel.

8. IP NSED has developed a plan to initially perform on-going technical reviews of 10%, or a minimum of one (1) per building,aof conduit support calculations performed by S&L during each month, to assure technical adequacy of the calculations. This Plan will be adjusted as experience is gained with the quality of the new calculations.

Generic Actions

9. Sargent & Lundy Quality Assurance has initiated audits in other areas of the Clinton design that used procedures similar to the conduit support and small bore pipe support procedures (repetitive calculations prepared by a large group of personnel, based on simplified procedural type of analysis) to assure that similar calculational errors do not exist. These areas include the following:

a. HVAC supports

b. Cable tray supports

c. Large bore pipe support auxiliary steel

d. Potential interactions

e. Instrumentation setpoints

f. Reinforcement of branch connections in piping and welded attachments to piping

g. Pipe whip restraints

h. Expansion anchors

10. their I Illinois technical Power NSED review and activities

/ audit QA are expanding's of S&L design. To l date, reviews of cable tray support design have been made and reviews of large bore piping design have been l initiated.

Safety Implications / Significance A review of calculation discrepancies in the area of electrical conduit supports and small bore / instrumentation piping supports has been performed by S&L and has shown the errors have no significance to plant safety. IP NSED will independently evaluate the results of the S&L evaluation for technical I

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Mr. Jam 2s G. Keppler Pago'8 March 28, 1983 adequacy. Further, a review of past calculations in the area of electrical conduit supports and small bore / instrumentation piping supports is presently on-going to determine the. adequacy of t'ae design. Any identified discrepancies will be evaluated to determine the significance to plant safety. The.results will also be analyzed for trends which will aid in identifying root cause and evaluating the need for additional generic corrective action. It is expected that an evaluation as to the reportability of this potential deficiency will be completed in approximately ninety (90) days.

We trust that this interim letter provides sufficient information to perform a general assessment of this deficiency.

and overall approach to resolution of the problem.

Sine rel 'ours,

. . Hall Vice President REC /ch cc: H. H. Livermore, NRC Resident Inspector Director, Office of I&E, USNRC, Washington, D.C. 20555 Illinois Office of Nuclear Safety Manager-Quality Assurance INPO Records Center l

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